Independent wheel suspension



Jan. 10, 1939. J. w LEIGHTON INDEPENDENT WHEEL SUSPENSION 7 OriginalFiled Nov. 25, 1955 m" VM Va m H m i nfi r 8 MW 0 Y 4. B 9

M Z ww m a fl Patented Jan. 10, 1939 INDEPENDENT WHEEL SUSPENSION JohnW. Leighton, Port Huron, Mich.

Original application November 25, 1935, Serial N 0. 51,396. Divided andthis application August 17, 1936, Serial No. 96,423

1 Claim.

The present invention relates to wheel suspensions, and particularly toconstructions of the individually sprung type, and this application is adivision of applicant's co-pending application Se- 5 rial No. 51,396,filed November 25, 1935.

It is an object of the present invention to provide an individual wheelsuspension so constructed that a change in the relative position of thevehicle wheels and the frame, such as results from the tilting of avehicle in rounding a curve, automatically causes the wheels to slantinto the curve.

It is a further object of the present invention to provide aconstruction as above stated in which, in rounding a curve, the upperedge of the inside vehicle wheel swings outwardly from the frame and theupper edge of the outside vehicle wheel swings inwardly with respect tothe frame.

It is a further object of the present invention to provide aconstruction as above stated in which each vehicle wheel is suspendedfrom the frame through a single wishbone member.

It is a further object of the present invention 25 to provide aconstruction as above stated in which the wishbone is pivoted at one endto the vehicle frame and a load transmitting spring is interposedbetween the frame and a point intermediate the ends of the wishbone.

It is a further object of the present invention to provide aconstruction as above stated, in which a tilting of the vehicle framecauses a corresponding tilting of the wishbone, and thus causes theassociated wheel to lean inwardly or outwardly with respect to theframe.

It is a further object of the present invention to provide a vehiclesuspension of the individually sprung type, embodying improved means tolimit upward movement of the vehicle frame with respect to a wheelsupporting wishbone.

It is a further object of the invention to provide an improved pivotalconnection between the wishbone and the vehicle and improved method ofassembling the wishbone with the connecting means.

With the above and other objects in view, which appear in the followingdescription and in the appended claim, an illustrative embodiment of thepresent invention is shown in the accompanying drawing, throughout theseveral views of which corresponding reference characters are used todesignate corresponding parts, and in which:

Fig. 1 is a fragmentary view in elevation of a preferred embodiment ofthe present invention;

Fig. 2 is a view in plan, taken along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view taken along the line 3-3 of Fig.2; and

Fig. 4 is a fragmentary sectional view taken along the line 44 of Fig.2.

In the illustrated form of the present invention, each individuallysprung wheel is suspended from the vehicle frame through a singlewishbone, of improved construction, and described in more detail below.The inner end of each wishbone is pivotally connected to the under sideof the frame at a point spaced from the longitudinal center line of thelatter, the connection being such as to permit relative movement betweenthe frame and the wishbone in a vertical plane. The illustratedarrangement is designed for front wheel suspensions, and the outer endof each wishbone, accordingly, is arranged to form a bearing for a kingpin, to which a knuckle bracket and wheel spindle are pivotallyconnected to permit steering of the vehicle. One end of a load springindividual to each wishbone is seated against the vehicle frame, and theother end is seated in a pan secured to the wishbone.

In operation, a tilting of the vehicle frame, such as occurs during therounding of a curve, causes the side of the frame on the outside of thecurve to move downwardly with respect to the outside wishbone, and theframe portion on the inside of the curve to move upwardly with respectto the inside wishbone. The downward tilting movement causes acorresponding downward movement of the inner end of the correspondingwishbone, which causes a corresponding tilting of the associatedspindle, and causes the top of the associated wheel to slant inwardlytowards the frame. The upward tilting of the frame causes acorresponding upward movement of the inner end of the correspondingwishbone and socauses the inside wheel to slant outwardly at the topwith respect to the frame. In operation, accordingly, the wheels eachslant into a curve, much in the manner of the wheels of motorcycles andthe like.

The tilting action has been found to materially improve the stability ofvehicles during operation, and to also substantially reduce tire wear byeliminating any slippage between the tires and the roadway, normallyincidental to the rounding of a curve. The broader aspects of thisfeature of the present construction are claimed in the copendlngapplication of the present applicant Serial Number 39,986, filed July18, 1935, which described an alternative construction, embodying a pairof spaced wishbones associated with each of the wheels.

In further accordance with the illustrated form of the presentinvention, an improved and simply applied connection is formed betweeneach wish-' bone and the frame to limit upward movement of the framewith respectto the wishbone. The limiting mechanism comprises a pair ofpivotally connected links, which are also pivotally connected to theframe and to the wishbone respectively. Normally, these two links are ata substantial angle to each other, but a raising of the frame withrespect to the-wishbone causes the links to straighten out, andultimately to provide a positive mechanical limit to the movement. Arubber bumper is also preferably provided to cushion the limitingmovement.

A further feature of the illustrated construction is the provision of awishbone formed entirely of metal stampings, which may be readily andeconomically manufactured, and which, while being sufliciently rigid forsatisfactory operation, is also sufiiciently resilient to enable it toabsorb a certain amount of the shock of operation. As illustrated, thewishbone comprises a stamping bent to provide a pair of spaced divergingarms, and an eye. The eye forms a bearing for the previously mentionedking pin. Openings are formed in the ends of the arms, within which ashaft is secured by a bearing connection which is preferably of thefreely rotatable threaded type. The shaft in turn is secured to theunderside of the vehicle frame by suitable brackets. Preferably, and asillustrated, a stiffening strut is connected between the legs at anintermediate point of the wishbone. The strut comprises a length ofstamped metal of generally U-shape, the legs of which are suitablysecured to the wishbone legs. The previously mentioned pan, which formsa seat for the vehicle load springs, is secured to the opposing legs ofthe wishbone, and also to the strut. A seat provided with an eye toprovide a threaded bearing connection with the previously mentionedlimiting links, is also secured between the opposing legs of thewishbone.

Considering the above mentioned elements in more detail and referring tothe drawings, the inner ends of the arms of each wishbone Ill arepivotally connected, by bearing assemblies designated II and I3, to theunderside of a cross member 82, of downwardly directed channel shape,which forms a cross connection between the vehicle frame member H andthe corresponding opposite frame member (not shown); and the outer endthereof supports a king pin l6 which forms a conventional pivotalsupport for a knuckle bracket l8' and spindle 20. As will be understood,a vehicle wheel (not shown) may be rotatably mounted upon the spindle20. An illustrative steering connection, which may be arranged in anyconventional way, is represented by the element 22. s It will beunderstood that the spindle and king pin assembly is such as to providethe usual castering angle for the wheel, and that the assembly for theopposite front wheel is correspondingly arranged. One end of a usualload spring 24, individual to each wheel, is seated within the crossmember I2, and the lower end thereof is seated upon a collar 26 securedwithin the pan 28, which, in turn, is suitably secured to the wishboneID by the rivets 30. A shock absorber is preferably utilized inconjunction with each spring 24, and maybe of conventional construction,such, for example, as the illustrated bicycle pump type 82, the upperend of which is pivotally secured to a clevis 34, by pin 35, and thelower end of which is correspondingly, pivotally secured by pin 38within a clevis 40 struck upwardly from the base of pan 28.

Each outer end of frame 52 is preferably provided with a bumper 52 whichcooperates with a rubber buffer 44 to limit downward movement of framel2 with respect to the associated wishbone l0. Upward movement of frame[2 with respect to wishbone ill is correspondingly'jlimited, inaccordance with the illustrated construction, by the pair of pivotallyconnected links 46 and 48. Links 46 and 48 are also pivotally connectedto the previously mentioned clevis 34 and to wishbone I0 respectively bythe connections designated generally 50, and thus are freely rotatablewith respect to each other and with respect to the frame and wishbonerespectively. The connections 50 may be arranged in various ways but arepreferably of the threaded type disclosed and claimed in Patent No.1,924,448, granted August 29, 1933, to the present applicant. Thedetails are omitted in order to simplify the drawing. An additionalrubber buffer 52 secured upon the upward and angularly disposed face ofthe bumper 42 cooperates with the link 66 to resiliently limit theupward motion of frame l2. The eye 41 to which the lower end of link 48is connected, is formed in a plate 49 which is suitably secured towishbone ID by rivets 5|.

In response to an upward movement of frame l2 with respect to eitherwishbone, the associated links 46 and 48 move from the illustrated andnormal positions to positions in which the angle between them isreduced. At a predetermined point in this movement, represented by thedesired limit to the upward movement of frame I2, buffer 52 is engagedby the underside of links 66, thus preventing further rotation of thelatter, and correspondingly interrupting the upward movement of theframe. It will be evident that through use of independent motionlimiting devices for the frame, the load springs may be freely seatedbetween both the frame and the pans, thus simplifying the assembly ofthe springs with these members. It will also be evident that theparticular motion limiting mechanism illustrated may be readily andeconomically manufactured and assembled with the frame and thewishbones.

Considering the construction and mounting of wishbone II) in moredetail, it comprises a single stamping bent to form a pair of divergentlegs and 62, and the eye 64. The inner ends of legs 60 and 62 are bentso that they are disposed in spaced parallel relationship. As previouslystated, the eye 64 forms a journal for the king pin it, and the innerends of the arms 60 and 62 are provided with openings to accommodate thepreviously mentioned bearing assemblies designated generally II and I3,through which wishbone I0 is connected to the cross-bar 66. The strut68, also preferably formed of stamped metal, is bent to define 'the legs10, which correspond in shape to the legs 60 and 62 respectively, andare secured thereto by the rivets I2. The previously mentioned pan 28 issecured to arms 60 and 62 and strut 68 by the previously mentionedrivets 30 and rivets 18. Additional support for pan 28 is afforded bythe outwardly turned flanges 76 thereof, which bear against the upperedges of the arms 50 and 62.

The cross bar 66 is provided with a pair of spaced integrally formedbrackets 80, through which it is securedto the underside of the framemember l2 by the studs 82, at a point to the right of the longitudinalaxis of the vehicle frame as viewed in Fig. 1. The respective ends ofbar 66 are externally threaded, as shown in the detailed Figures 3 and4. The threaded bearing connections H and I 3 are preferably of thealternateftype as shown and described in the copending application ofthe present applicant Serial No. 698,715, filed November 18, 1933. Theconnection ,ll includes the bushing 84, which is provided with internalthreads which mate with a bearing fit with the corresponding threadsformed on the associated end of bar 66. Bushing 84 is also provided withexternal threads of the same pitch, but cut substantially lighter thanthe internal threads, which loosely mate with corresponding threadsformed in the end of arm 62 and the strut 68. The connection I3 issimilarly constructed with the exception that the bushing 86 is adaptedto be slidably received within the end l8 of the arm 68 and strut 68.Bushing 86 is provided with a hex head 88, which engages a locking lug98 when the parts are in assembled position to prevent rotation betweenbushing 86 and arm 68 and strut 68. Preferably, the ends of bushings 84and 86 are closed by Welch washers 92 which are constructed toaccommodate the usual lubricant fittings 84.

In assembling the parts, the arm 68, for example, is moved over theassociated end of cross bar 66 far enough to permit the other arm 62 tobe swung to a position in which the opening therein is in alignment withthe associated end of bar 66. Thereafter, the wishbone I8 is centeredwith respect to bar 66, and the bushing 86 is threaded onto the end ofcross bar 66. When the inner face of the hex nut 88 engages the lockinglug 88 on arm 68, further rotation of the former causes cross bar 66 tomove outwardly through the corresponding opening. The threading ofbushing 86 is continued until bushing 86 reaches approximately the finaldesired position on cross bar 66. At this time. one face of the hex nut88 is brought to the position shown in Fig. 2, in which it can be slidunder the locking lug 98, and bushing 86 and cross bar 66 may be slidthrough the opening in arm 68 and strut 68 to substantially the originalaligned position. After being thus slid to the aligned position, lug 88acts to positively prevent further rotation of bushing 86. Thereafter,bushing 84 may be threaded on the associated end of cross bar 86 andinto the cooperating opening in arm 62 and strut 68. Bushing 84 isturned until theshoulder formed by the hex head 96 thereof engages theouter face of arm 62. At this time, the lightly cut external threads onbushing 84, and correspondingly cut internal threads in arm 62 and strut68 lock together by a jamming action, positively preventing furtherrotation, of bushing 84.

As previously stated, the pitches of the external and internal threadsof bushings 84 are substantially the same, so that during the threadingin of bushing 84, substantially no movement of cross bar 66 occurs. Anyslight movement occurring, however, because of manufacturing tolerancesor the like, is taken up by the slidable connection between bushing 86and arm 88 and strut 68, and does not change the spacing between theinner ends of arms 68 and I2. It has been found in practice, that theresilient characteristics of the stamped metal wishbone ID are such thatthe wishbone may itself absorb any such movement of cross bar 66.Preferably, however, the alternate types of threaded hearing connectionconstructions are utilized, in order to reduce the stresses which wouldotherwise be imposed on the arms 68 and 62.

Considering the wheel tilting action of the wishbones, itwill beunderstood that any tilting of the vehicle frame [2 occurring during therounding of a curve for example, takes place about the longitudinalcenter line of the frame as an axis. Since, as stated, the connectionbetween the inner end of each wishbone is spaced from the longitudinalaxis of the vehicle, it will be evident that a downward tilting of theright hand end of the vehicle frame l2, as viewed in Fig. 1, causes acorresponding downward movement of the inner end of the correspondingwish bone l8. This downward tilting of the inner end of wishbone l8causes a corresponding tilting of spindle 28 and hence causes the top ofthe associated wheel (not shown) to lean inwardly with respect to theframe. Similarly, an upward tilting of the right hand end of frame l2,as viewed in Fig. 1, causes an outward tilting of the top of the wheelwith respect to the frame. It will be seen, accordingly, that when. inrounding a curve, the outside frame side tilts downwardly, and theinside frame side tilts upwardly, these tilting movements cause theinside and outside wheels to lean into the curve.

Although a specific embodiment of the present invention has been shownand described, it will be evident that various changes in the form,number and arrangement of parts may be made within the spirit and scopethereof.

What is claimed is:

In an individual wheel suspension, 8. vehicle frame, a rigid arm pivotedat one end to said frame on a substantially horizontal axis, a wheelsupporting member pivoted directly upon said arm on a substantiallyvertical axis, a load spring between said frame and said arm, a leverpivoted to said frame on a horizontal axis, a link connecting said armand lever adjacent the free ends thereof, and abutment means on theframe engageable with an intermediate portion of said lever to limitpivotal movement of said arm and lever in one direction.

JOHN w. LEIGHTON.

